Prachett based Ankh-Morpork on 18th century London, but he knew his history. Some aspects of Ankh-Morpork were based on Rome (Republic and Empire) and others based on 16th century Italy. Forex, 'The Patrician' is a clear callback to the Medici and Machiavelli.
> https://en.wikipedia.org/wiki/Lord_Vetinari